[Simulation and Observation of Vertical Cast-off Bloodstain Pattern].

OBJECTIVE: To observe the characteristics of vertical cast-off bloodstain pattern by different hitting-tools. METHODS: The regular hitting tools, a kitchen knife, a dirk, a plane set-hammer and an iron pipe, were selected. At a distance of 30 cm away from the wall, the hitting tool with 5 mL fresh chicken blood made the cast-off bloodstain from top to bottom. Then the holistic distribution characteristics (length, width and density) of cast-off bloodstain and morphology characteristics (length, width and contact angle) of first single cast-off bloodstain were analyzed. RESULTS: The distribution length of cast-off bloodstain formed by dirk was minimum (P < 0.05). The distribution width of cast-off bloodstain formed by kitchen knife was minimum (P < 0.05). Except the pair of kitchen knife and plane set-hammer, the distribution density between each two tools had statistical differences (P < 0.05). The length of first single cast-off bloodstain formed by plane set-hammer was longest compared (P < 0.05). The width of first single cast-off bloodstain had statistical differences between kitchen knife and plane set-hammer, and between dirk and plane set-hammer (P < 0.05). CONCLUSION: The type of hitting tool could be inferred by the specific characteristics of cast-off bloodstain pattern formed by every specific type of hitting tool in crime scene.

Difference in proinflammatory cytokines produced by monocytes between patients with major depressive disorder and healthy controls.

BACKGROUND: Immune activation and suppression in patients with major depressive disorders (MDD) have been both reported in different studies. We assume that these findings may indicate innate immunological tolerance in MDD, with subclinical elevated level of proinflammatory cytokines and the decrease in innate immune response while encountering pathogens. METHODS: Peripheral monocytes of 50 untreated patients with MDD and 40 healthy controls were isolated and cultured, with or without 10 ng/ml lipopolysacchride (LPS) for 6 h (6 h, LPS+/-), and with LPS for 18 h (18, LPS+). The cell culture supernatants were collected to measure concentrations of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and interleukin 1 beta (IL-1ß). RESULTS: The baseline concentrations of IL-6 and IL-1ß (6 h, LPS-) were significantly higher in the MDD group than those in the control group. There was no significant difference of TNF-α between the two groups. The fold changes of LPS-induced secretion of IL-6 and TNF-α from monocytes cultured for 6 and 18 h were all lower in the patient groups, and that was true for IL-1ß as monocytes cultured for 18 h. LIMITATIONS: Given the gap between the results of in vitro experiments and the actual response that happens in vivo when the immune system encounters pathogens from the external world, future research should include in vivo methods to test the results of the current study. CONCLUSIONS: Patients with MDD may have subclinical inflammation during a depressive episode, and the reduced response to LPS in monocytes indicates innate immunological tolerance.